What ultimately is the idea behind STEEMIT in relation to the future of STEEM? I am trying to wrap my head around this all...

Is it to keep people interested and create a strong community?
Kind of like a self marketing system?

I am trying to understand where the idea originated and what the vision was/is...

Votes, Rewards, Witnesses, Power Ups, Power Downs, Pay Outs (50%/50% or 100%??... Is there any easy way to explain it?